I've used Waze in the UK for a two years, and just had two weeks in the US and noticed that FourSquare check in was available and worked when I was in the UK, but didn't show as a menu option (either separate button, or under Friends) when I was in the US and still doesn't show now that I'm back in the UK.

Closures never showed when I was in the UK, it did when I was in the US, and still shows now that I'm back

Sounds like version changes have coincided with your travel as there are no discernible differences between the functions you mention in UK and US. However the foursquare button was recently removed from the front menu.